Determination and optimization of Bacillus subtilis traits required for its establishment, persistence and activities on plant roots

点击翻译按钮获取中文摘要

Microorganisms are essential for the good health of biotic ecosystems. Thus, use of plant-beneficial bacteria as organic amendments for increase growth and pathogen protection in agriculture is a promising alternative to the current over-usage of chemicals. While many of these products are already on the market, inconsistence in their efficacy is a major hurdle to their widespread usage in fields and greenhouses. Bacteria from the Bacillus genera, and in particular of the subtilis and velezensis species, are of central interest in the development of biological solutions in agriculture. These bacteria possess many plant growth-promoting (PGP) traits, such as direct stimulation of the metabolism of the plant, and aid for the plant to acquire diverse nutrients. Most Bacillus species secrete an arsenal of antimicrobials and favor the plant resistance's toward pathogen infections, thus acting as natural, biological pesticides and fungicides. Bacillus species can also form resistant endospores, a dormant state ideal for product formulation. Fundamental questions about the interaction between beneficial Bacillus and plants are still unanswered, which slows down our capacity to formulate consistently efficient products. In this research program, we will explore three fundamental questions with the aim of better understanding the complex interactions between Bacillus species and plants. First, we will determine what are the environmental conditions that modulate dormancy of Bacillus on roots. In the same objective, we will also evaluate if Bacillus spores can still exert beneficial effects on plants. Secondly, we will identify what are Bacillus cellular components that are critical for the establishment and persistence on roots in absence and in presence of competing strains. Finally, we will evaluate to what extent Bacillus beneficial activities are expressed when it is on plant roots, and how to potentiate their activities in natural conditions. This research program will lead to a fundamental comprehension of in planta interactions of B. subtilis and plants, providing key information for the future development, usage and formulation of this biological growth promoter and pesticide. These knowledge are very important, since they are necessary to develop and implant sustainable agricultural systems.